A magnetic field is used in Magnetic Resonance Imaging to align the nuclear spins of atoms as part of the procedure for producing images within the body of a patient. This magnetic field is referred to as the B0 field. During an MRI scan, Radio Frequency (RF) pulses generated by a transmitter or amplifier and an antenna cause perturbations to the local magnetic field and can be used to manipulate the orientation of the nuclear spins relative to the B0 field. RF signals emitted by the nuclear spins are detected by a receiver coil, and these RF signals are used to construct the MRI images.
Parallel Transmit Magnetic Resonance Imaging (MRI) systems may have multiple transmit and receive channels. The antenna may comprise multiple antenna elements, each of which is connected to a transmitter and/or receiver.
U.S. Pat. No. 7,282,915 discloses a receive only RF imaging coil. The RF imaging coil has a plurality of distributed capacitors positioned selectively about each coil element. The values of the distributed capacitors are adjusted so as to tune each coil element to the MRI frequency with all the coil assemblies assembled and with the sample or subject present in the sample space.